Touch Panel, also known as Touch Screen or Touch Control Panel, is an induction type display device that is able to receive input signal from a contactor or the like, and it is widely used in various electronic products. According to different operation principles and information transmitting media, there are four types of Touch Panels: resistance type, capacitive type, infrared ray type, and surface sound wave type.
Capacitive Touch Panel (abbreviated as CTP) controls the screen by utilizing electric current induction of a human body. On the basis of detected change of electric capacity of the contacted area, the location of the contacting finger is calculated with accuracy up to 99% and respond time less than 3 ms. Since CTP has advantages such as high sensitivity and easily achievable multi-point touch control, CTP gradually becomes a mainstream Touch Panel applied in electronic products such as smart-phones and tablet computers.
In prior art, according to the relative position between the touch control stacked layer structure and the display panel, CTP can be divided into different technical architectures of out-cell (the touch control device is hanging out of the display panel), on-cell (the touch control device is configured on the display panel), and in-cell (the touch control device is integrated within the display panel). Although the out-cell technology and the on-cell technology are mature and have been widely used along with medium and small sized display panel, and OFS (One Film Solution) of the out-cell technology can be used in an organic electro-luminescent display device to make it possible for flexible touch control display, however, the in-cell technology can make the display panel lighter and thinner, with higher light transmittance and lower power consumption, as well as achievable flexibility, and therefore the in-cell technology is considered to be an ultimate solution for touch control display, especially for touch control of organic electro-luminescent display, which will gradually become a development mainstream of touch control technology in organic electro-luminescent display devices.
Chinese patent literature CN101635276A discloses an organic light-emitting diode touch control panel which comprises a substrate, an OLED component, and a light sensing component. At least one pixel area is defined on the substrate, and a display area and a sensing area are defined in the pixel area. The OLED component is configured in the display area on the substrate and comprises a first thin film transistor, a light-emitting lower electrode part, a patterned organic light-emitting layer, and a light-emitting upper electrode part. The light-emitting lower electrode part is configured on the substrate and electrically connected to the first thin film transistor. The patterned organic light-emitting layer is configured on the light-emitting lower electrode part. The light-emitting upper electrode is configured on the patterned organic light-emitting layer. The light sensing component is configured in the sensing area on the substrate and comprises a second thin film transistor, a light sensing lower electrode part, a patterned light sensing dielectric layer, and a light sensing upper electrode part. The light sensing lower electrode part is configured on the second thin film transistor and electrically connected to the second thin film transistor. The patterned light sensing dielectric layer is configured on the light sensing lower electrode part, and the light sensing upper electrode part is configured on the patterned light sensing dielectric layer. The product of this patent has high sensitivity, but pertains to an in-cell type light touch control device which not only has complicated structure and preparation process but also is difficult to achieve multi-point touch control, so that it does not belong to mainstream touch control technology.